A810, A1300, A2300, A2400 A3400 & A4000 updates from nafraf:
http://chdk.setepontos.com/index.php?topic=650.msg100529#msg100529
Updates for firmware stub generation:
- update finsig_vxworks.c to comment out entries overridden in stubs_entry_2.S (avoids generating unused code)
- simplify stubs_asm.h by removing NSTUB macro
- fix stubs_auto.S generation for IXUS 30, IXUS 40 and SX210
Fix message box not being erased properly in some cases.
Add 'User Menu Editor' module.
Extend User Menu and user menu editor to support adding simple modules to the User Menu.